Lubricating oil



Patented Nov. 21, 1944 2,383,184 e e LUBRICATING on.

Rush Fox McCleary, Beacon, N. Y., asslgnor, by mesne assignments, to The Texas Company, New York, N. Y., a corporation of Delaware No Drawing. Application April 26, 1941,

' Serial No. 390,541

("erase-4.7) 1

11 Claims.

This invention relates to an improved lubrieating oil adapted for use in internal combustion engines and particularly to a lubricating oil having one ormore additive ingredients incorporated therein. 3

It is generally conceded that in the recent development of internal combustion engines, and particularly engines designed for heavy duty service, the increase in operating temperatures, together with the reduction of clearances and the use of hard bearing alloys, such as copper-lead, cadmium-silver, etc., has set up such severe operating conditions as to necessitate an improvement in the highly solvent refined mineral oils refined for use as lubricants. These rigorous operating conditions, which are most prevalent in Diesel and gasoline engines used in heavy duty bus and tracto service, where the piston ring temperatures range from approximately 425 to 650 F. and pressures from the oxidizing combustion gases are as high as 750 to 1150 pounds per square inch, have seriously accentuated such problems as corrosion, oxidation and resin formation in the solvent refined mineral lubricating oils with the resultant deleterious effect on the efliciency of the engines. The nature and extent of these problems depend upon the conditions of operation of the particular engine type, the type and extent of refining of the base oil used, and numerous other factors.

.The tendency of mineral lubricating oils to deposit gums, resins, soot, and varnish-like materials about the valves, rings, pistons, cylinders and other engine parts can be largely overcome by the addition of certain types of additive ingredients which possess detergent qualities when dissolved or dispersed in lubricating oils. By detergent property is meant not only that property which aids in dispersing, removing or purging foreign materials which accumulate on the surface of the engine parts but also that property which prevents the accumulation or deposition of such materials as distinguished from solvent action upon those accumulations or deposits.

In addition thereto, the added tendency of these oils to corrode the metal surfaces with which the lubricating oil comes in contact may be overcome or reduced by the addition of additive components which possess anti-oxidant or anti-corrosive properties when dissolved or dispersed in mineral lubricating oils. These antioxidant or anti-corrosive properties are meant to include all such properties which effect a reduction or elimination of weight loss of the lubricating surfaces, particularly bearing surfaces, which results from the corrosive action of the mineral lubricating oil.

It is the object of the present invention to provide a mineral oil composition which possesses the above-mentioned detergentand anti-oxidant or I stability in service andstorage and improved load-carrying capacity by incorporating in a mineral lubricating oil a novel additive ingredient of multi-functional activity.

A further object of this invention is to provide a mineral oilcomposition possessing detergent properties and enhanced anti-oxidant or anti-corrosive properties by combining with the above-mentioned multi-functional' additive an auxiliary additive ingredient and' incorporating in a mineral lubricating oil.

The invention is based upon the discovery of a novel class of multi-functional additives which may be broadly described as oil-soluble or oilmiscible alkyl substituted ,aryloxy or aryl thiooxy tertiary amines and/or the metal derivatives thereof. It has been found that when small proportions of a compoundwithin the scope of the above general class are blended with a mineral lubricating oil, a mineral oil composition is formed, possessing excellent detergent, anti-oxidant or anti-corrosive, stabilizing, and load-carrying (E. P.) properties.

The compounds of the present invention'may be further described as oil-soluble reaction products of the treatment of any methylol forming aromatic compounds with formaldehyde and any secondary amine and/or their corresponding metal derivatives. These. products may be represented by the following structural formula in which B may be a hydrogen, alkyl, aryl, aralkyl, cyclo-alkyl or naphthenyl radical. These radicals may contain further substituents which do not affect the oil-solubility of the compound, as, for example, halogen, sulfur, oxygen, or nitrogen derivatives. R1 and R2 may be alkyl, cycloalkyl, aralkyl, naphthenyl radicals or substituted derivatives thereof and they may be combined to form a heterocyclic radical with the nitrogen of the aminomethyl group. Also R1 and R2 may be dissimilar radicals within the scope of the abovementioned radicals. X may be either an hydroxyl (OH) or sulfhydryl radical (SH) or metal salts thereof, and n, y, a may be integers of 1 or more. :1; and 2 may be either 1, 2, 3, or 4, while 1: may be either 1, 2 or 3, depending upon the valences of the aromatic nucleus not satisfied by other substituents or the residual hydrogen. The aromatic nucleus diagrammatically shown may be substituted by a naphthyl, anthracyl or other condensed aromatic nuclei. The positions of the n, 11, 2:1 Piperazinomethyl amylphenol n, 11-1, z=2 Di (piperidinomethyl) undecyl phenol n=1,y 2, 1 Di (diamyl hydroxybenzyl) piperazine n=1, 1;, z=2 Di (morpholinomethyl) dioctyl phenol n=2, 1 z=1 Morpholinomethyl octadecyl resorcinol n=-2, y==1, z=2 Di (morpholinomethyl) octyl resorcinol n, y=2, z=1 Morpholinomethyl dloctyl resorcinol R=hydrogen, R1 and R2 forming a heterocyclic radical with nitrogen. of the aminomethyl group Plperazinomethyl phenol n=1, y==3, z=2

Di (morpholinomethyl) phenol n=-1, y=2, z=3

Tri (morpholinomethyl) phenol u, M Di (piperidinomethyl) resorcinol R=alkyl, R1 and R2 are dissimilar radicals 11, Methylethylaminomethyl octyl phenol n, 11:1, z==2 Di (methylethylamlnomethyl) octyl phenol R=cycloalkyl, R1 and R2 are dissimilar radicals l1, z=1 Methylethylaminomethyl cyclohexyl naphthol n, y=1, z=2 Dl (methylethylaminomethyl) cyclohexyl naphthol R=hydrogen, R1 and R2 are dissimilar radicals n=-1, y=2, z=3 Tri (methylethylamlnomethyl) phenol R=aryl, R1 and R2 are dissimilar radicals in, y, z-=1 Methylethylamlnomethyl p-phenyl phenol This general class of compounds may be prepared by any of the classical methods of synthesis and the following examples are mentioned as illustrating one method of preparation:

EXAMPLE 1 at 25-30 C. for one hour during the addition of the formaldehyde. After the addition was complete the temperature was increased to 70-75 C. for one hour. The product separated out as an oil and was washed well with water and then dried by warming to 75-80 C. in vacuo. The dimethylaminomethyl tridecylphenol was a light brown colored oil with a slight amine odor.

EXAMPLE 2 200 grams (0.76 mol) of a dimethylaminomethyl octyl phenol, prepared in accordance with the procedure given in Example 1, were dissolved in 250 cc.,of benzene and grams (0.38 mol) of anhydrous barium hydroxide were added with stirring. The solution was heated to reflux under an automatic water separator until no more Water was evolved, Filter-eel and additional benzene were added and the excess barium hydroxide filtered out. The clear filtrate was freed of solvent by heating to IS- C. in vacuo. The resulting barium dimethylaminomethyl octylphenolate, represented by the formula CaHn asa

Cali

Cfia CHa C CHs appeared as a dark brown, oily residue which solidified to a pasty solid on cooling which was very soluble in oil and gave the following analysis: ash, 23.5%; ash (theoretical) 23.3%.

The proportions of these multifunctional additives added to a mineral lubricating oil may vary between 0.1 and 5.0% by weight, depending upon the particular base oil used and the type of engine and service involved. However, the range of proportions between 0.25 and 2.0% by weight has been'found to be particularly effective in imparting excellent detergent, anti-corrosive, and loadcarrying properties to the mineral lubricating oil.

An additional feature of the present invention is a combination of the foregoing multifunctional additives with an auxiliary additive to further enhance the anti-oxidant or anti-corrosive properties of the mineral oil composition with which the additives are used in certain Diesel and gasoline engines designed for heavy duty service, A higher degree of anti-oxidant or anti-corrosive properties is desired and it is for this purpose that an auxiliary additive ingredient is added to the compounds aforementioned.

The class of compounds which may be used to impart the additional anti-corrosive properties may be any one of the generally accepted sulfurized anti-corrosives. Among the particularly effective sulfurized anti-corrosive compounds found suitable for purposes of the invention are the sulfurized esters of oleic acid, such as sulfurized ethyl oleate; sulfurized high-boiling gasoline polymers,

such as the sulfurized clay tower polymers; sulfurized fatty oils, such as sulfurized sperm oil; sulfurized wax compounds, such as sulfurized paraffin wax; sulfurized resins, such as sulfurized abietene; sulfurizecl tall oil and sulfurized terpene hydrocarbons, such as the sulfurized terpinolenes and isomers thereof which are disclosed and claimed in the copending application of Knowles et al., Serial No. 391,468, filed May 2, 1941. The amount of sulfurized compound added to the mineral lubricating oil in combination with the multifunctional additive is usually within the proportion range of 0.5 and 5.0% by weight and preferably between 1.0% and 3.0%, depending upon the type of lubricating oil used.

These sulfu'rized auxiliary additives may be prepared in accordance with the copending applications of Knowles et al., Serial Nos. 358,876, 358,877 and 358,878, respectively, all filed September 28, 1940, wherein a light-colored sulfurized material is prepared by the direct action of sulfur to the material to be sulfurized at approximately 800 F. in the presence of water and under pressure of hydrogen sulfide. This pressure which is at least 50 pounds per square inch, is maintained until all the free sulfur has entered into combination and lasts usually fromone-half to three hours. The sulfurized products formed by this process are directly soluble in a mineral oil and possess the added advantage in that the reaction product is a light-colored compound as against theusually dark-colored sulfurized compounds.

As illustrative of the anti-corrosive properties of a lubricating oil containing either or both of the aforementioned class of compounds, the results of the following empirical tests are presented: A copper-lead bearing specimen, encased in a special non-wear bushing and rotatably mounted on a stainless steel shaft, was immersed in a glass pot of the oil to be tested. The tested oil was heated to a controlled temperature of either 250 F. or 350 F. and continuously circulated between the bearing specimen and the shaft for; ten hours. The bearing specimen was weighed before the test and after the ten hour periodand the loss in weight recorded in milligrams. Two reference oils were used throughout this test and will be referred to as reference oil A and reference oil B. Both of these reference oils were solvent-refined, dewaxed Mid- Continent lubricating oil distillates of SAE 30 grade,- reference oil A being a' paraffin base oil and reference oil B being a paraffin -naphthene (1:1) base oil. To these reference oils were added varying proportions of the additives of the present invention taken individually and in combination and the results compared. The results of two runs-at both 250 F. and 350 F. are presented:

BEARING CORROSION, -COPPERLEAD Hones) Loss of weight in mgs.

Reference oil 8" plus 0.5% barium dirnethylaminomethyl octylphcnolate plus 1.0% sulfui'izedterpinolcne 0, 0

Reference oil plus 0.5% barium dimethylaminomcthyl octylphenolate plus 2.0% sulfurizcd ethyl oleate Reference oil Li plus 0.5% barium dimethylnmincmethyl octylplienolate plus 3.0% sulfurized clay tower polymers In order to illustrate the aforementioned dete gent properties of the additives of the present invention an empirical test was devised which would illustrate the ability of the multifunctional additives to disperse, remove or purge carbonaceous deposits from the engine surface of a heavily varnished engine. A heavy varnish deposit was obtained .upon, the piston of a single cylinder standard Lauson engine by utilizing a solvent refineddswaxed Mid-Continent lubricating oil of an SAE 10 grade and running the engine at 1800 R. P. M. with a jacket temperature of 2l2 F., a crankcase temperature-of-300" F. and with a crankcase ventilation of 0.4 cubic feet of air per minute for 24 hours. Then, without cleaning the piston the oil was changed to the iii compounded oil containing the proposed additives and the engine operated at 1800 R. P. M. with a jacket temperature of 315 F., a crankcase temperature of 200 F., and with no crankcase ventilation for 20 hours. At the end of the 24 hour period the engine was dismantled, the condition of the piston noted and the oil classified according to a visual inspection of bad, fair and good. The following results were obtained with a solvent-refined, dewaxed Mid-Continent lubricating oil of an SAE 30 grade as reference oil, together with this reference oil compounded with the proposed multi-functional additives.

LAUsoN DETERGENCY Tas'r A further illustration of the detergent properties of the multifunctional additives may be shown by the results of an empirical test which was-"designed to indicate the performance of the additives in preventing the accumulation or deposition of varnish or lacquer deposits on the engine parts. cylinder standard Lauson engine by operating with the compounded oil of the present invention under extremely severe conditions for the purpose of developing varnish and lacquer. The conditions of operation attempt to simulate the severe operating conditions encountered in the field by running the engine'continuously at 1800 R. P. M. for 24. hours, with the jacket temperature at 212 F., the crankcase temperature at 300 F., fuel fed at 10 cc. per 30 seconds, and a crankcase ventilation of 0.4 cubic feet air per minute. At the end of this period the engine was dismantled, the condition of the piston noted, and the oil classified according to a visual classification of A, B, C, D, and E (A=clean; B=light varnish; C=medium varnish; D=heavy varnish;

and E=very heavy varnish). The following results were obtained with a solvent-refined, dewaxed Mid-Continent paraffin base lubricating oil of an SAE 10 grade as reference oil A and a solvent refined dewaxed Mid-Continent paraffin naphthene (1:1) base lubricating oil of an SAE 20 grade as reference oil B, and compared with the reference oils containing a multifunctional additive.

LAUSON VARNISH TEST.

Oil tested Rating i Reference oil A E Reference oil A plus phenol 0 Reference oil B E Reference oil B+0.5% be tylphenolate This test is carried out in a single scope thereof and therefore major proportion of v and N heterocyclic the methylene group through the nitrogen atom,

The multifunctional additives of the present invention may further be used in combination with other additive ingredients such as pour point depressors, oillness agents, extreme pressure agents, blooming agents, viscosity index improving agents, color stabilizers, etc.

Obviously many modifications andfvariations of the invention, as hereinbei'ore set forth, may be made, without departing from thespirit and only such limitations should be imposed as are indicated "in the appended claims. Iclaim: I 1. An improved lubricating oil comprising" a mineral lubricating oil having incorporated therein a small proportion of an oil-soluble compound which is the reaction product of a methylolforming aromatic compound with equimolecular quantities. of formaldehyde and a secondary amine in the ratio of one mol of the methylolforming aromatic compound to substantially three or more molsof both formaldehyde anda secondaryamine.

2. An improved lubricating oil comprising a a minor proportion of an, aromatic compound containing.. least three tertiary aminomethyl radicals linked to the aromatic nucleus through the methylene group and at least one substituent selected from the group consisting-of hydroxyl and sulfhydryl radicals.

3. An improved lubricating oil adapted for use in internal combustion engines, comprising a mineral lubricating oil containing a small amount of a compound of the following general formula 1 wherein R'is a radical selected from the group consisting of hydrogen, alkyl, aryl, aralkyl, cycloalkyl, and naphthenyl radicals, Q is a radical selected from the group consisting of N R. R, radicals which are, bound to R1 and R: are selected from the group consisting of alkyl,

selected from the group consisting of hydroxyl and sulfhydryl radi-' cals, n and 1! are integers of at least 1, and z is an integer of at least 3. i

a mineral lubricating on and whereinR is a radical selectedfrom the group" cycloalkyl, aralkyl and naphthenyl radicals, X is a substituent wherein R is a" radical selectedIfroi n the group consisting of hydrogen,

hydroxyl and sulfhydryl radicalsfit and flar ln tegers of at least 1 and 21 is an integer of least 3.

5. An improvedlubricating oil adapted for lubication of internal combustion engines, ,comprising a major proportion ofaminerallubricating oil ,and a minor-proportion of an, aryl. compound I containing at least v three tertiary amine substit. uents which is linked .;to said aryl compound through a methylene radicaLLand Hat least one substituent selected; from the group-consisting of hydroxyl and 'sulfhydryl radicals.

. 6. An improved lubricating oiladapted for engines, comprising a in internal combustion I mineral lubricating oil having incorporated therein a small proportion of a compound of the. followinggeneralformula consisting of hydrogen, alkyl, aryl, arallcyl, cycle-L alkyl, and naphthenyl.radicals,- R1 and R2 are selected from thegroup consisting of 'alkyl, cyclo alkyl, aralkyl, and naphthenyl radicals, x is a integers of at least 1, and least 3.

4. An improved lubricating oil adapted for use substituent; selected from v the group consisting of hydroxyl and sulfhydryl radicals, and]; are 2 is an integer of at "I. An improved lubricating oil adapted for use in internal combustion engines, comprising a. mineral lubricating oil containing 0.1 to 5.0% by weight of a compound of the following general formula wherein R is a radical selected from the group consisting of hydrogen, alkyl, aryl, aralkyl, cyclo-' alkyl, and naphthenyl radicals, Q is a radical selected from the group consisting or and Nheterocyclic radicals which are bound to the methylene roup through the nitrogen atom, R1 and R: are selected from the group consisting of alkyl, cycloalkyl, aralkyl, and naphthenyl radicals, X is a substituent selected from the group consisting of hydroxyl and sulfhydryl radicals, n and 1 are integers of atleast 1, and z is an integer of at least 3. i

8. An improved lubricating oil adapted for use in internal combustion engines, comprising a mineral lubricating oil having incorporated therein wselectedifrom;theigroup. consisting orcalkyl, cyclozalk'yl, aralkykand "naphthen'yl iradio'als, ."X is :a. substituent;seleote'dlfrom' itheygroup consisting 10f ghydroxylxand ssul'thydrylrradioals, n and :y are izintegersu-di'i-at ileastiral, sand 'z :is tan-integer of at a9. mm improved P lubricating -.oil adapted for ;use

.in Jinternal icombu'stion engines, comprising a aminerallubricating oil having incorporated. therevlinia-ieimallgiroportipn of ca compound or the folnowinms n i v wherein R 18718; radical selected from the group consisting:ofhydrogen,salkyl; aryl; aralkyl, cycloalkyl; i'and rnaphthenyl radicals;- R1 :and R: are :rsialectddrom athe -;.group "consisting of alkyl, cy- *QGIOQIRYI, :aralkylprand maphthenyl radioa1s,"n and are zintegersn 0115i; :ieas't i1,=and z is-v an integer *bi'ratdeastf 3.

LL10. -;-An'*improvediluiiricating1oilv adapted for use :;in i=internal -::oombustion :enzines," comprisin .minerallubricatm: oilhavin: incorporated therewherein-R.isaa'radical:selected from the group consisting of hydrogen, alkyl; aryl araikyl, acycloaaikyl,'=and=rnaphtheny1:sradicals, R1 and R2 are inasmallxproportionoi a compound or the 01- "lowing.general' tormula in OH whereiniRis aradical' selected from the group consisting of hydrcgemalkyl aryl,varalkyl, cyclo- "ialkyl, and 'naphthenyl :radicals, R1 land-R2 are.

selected from'the group consisting of alkyl, cyclo- .alkyl,:ar'a1kyl, and naphthenyl radicals, n and y are integers ofat least 1 and z is an integer of 'atieast 3. i

11. A viscous petroleum oil fractionhaving in admixturextherewith a'minor proportion of the 'reactionproduot obtained by reacting substantially equi-molecularvproportions or three or more mols of arcompound having a the. general iormula wherein R1 --and -R2 are :selected: from the group oonsistinghof'alkyl aralkyl and cyclo-alkyl radicals, and three or more. mole of formaldehyde,

1with one-mol-otia compound having the general formula wherein"Rrista monocyclloaromatic radical and =niis aawhole number from 1 to 3; said'rea'ction product possessing anti-oxidant properties and being presentin an amountrsufficient to inhibitthe deleterious 'efiects of oxidation in the oil.

RUSH FOX MCCLEARY. 

